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प्रश्न
Find the odd one out and give its explanation.
विकल्प
Tinning
Alloying
Anodization
Froth floatation
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उत्तर
Froth floatation
Explanation-
Froth floatation is a method used for the concentration of ores while others are methods used for the prevention of corrosion.
APPEARS IN
संबंधित प्रश्न
Give two examples of alloys with their chemical composition.
Why do we apply paint on iron articles?
Explain the term corrosion.
Give reasons:
Platinum, gold and silver are used to make jewellery.
Explain how painting of an iron gate prevents it from rusting.
Write a chemical equation to show the process of corrosion of iron.
What type of chemical reaction is involved in the corrosion of iron?
Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.
Explain why, iron sheets are coated with zinc.
Name five methods of preventing rusting of iron.
Name a common metal which is highly resistant to corrosion.
A common metal which is highly resistant to corrosion is:
(a) iron
(b) copper
(c) aluminium
(d) magnesium
In stainless steel alloy, iron metal is mixed with:
(a) Cu and Cr
(b) Cr and Ni
(c) Cr and Sn
(d) Cu and Ni
Brass is an alloy of:
(a) Cu and Sn
(b) Cu and Pb
(c) Pb and Sn
(d) Zn and Cu
Mention two uses of the following metals and non-metals
Iron
Name the metal which is a constituent of blood pigment?
Name the metal which is a constituent of plant pigment?
State under what conditions corrosion is faster ?
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
What is done to prevent corrosion of metals?
What are the adverse effects of corrosion?
What is ‘rusting’?
Answer the following question.
List two properties of alloys.
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
Give reason for the following:
A suspension of rust is basic in nature.
Rusting of iron : Fe2O3 : : corrosion of copper : ______
Write the name.
An alloy of copper and tin-
Draw a neat labelled diagram.
Electroplating
Draw a neat labelled diagram.
Anodizing
Observe the following diagram and give answers.
- Name this method of prevention of corrosion.
- For prevention of which metal this method is used?
- What is used as anode in this method?
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
What is rust?
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
Copper objects lose their shine and form green coating of ____________.
Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
A man painted his main gate made up of iron, to
- prevent it from rusting.
- protect it from sun.
- make it look beautiful.
- make it dust free.
Which of the above statement(s) is/are correct?
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
Gold plated ornaments is the example of ______.
